1. Field of the Invention
The present invention relates to a new device for lifting and moving manhole covers. More particularly, the present invention relates to a dolly on wheels equipped with a pivotal sleeve into which a lift bar fastens and equipped with a bottom plate with a tail on its bottom side.
The lift bar has a pointed end and a finger end and can be inserted into the sleeve so that either end of the lift bar can be used in conjunction with the bottom plate and tail to engage and lift a manhole cover.
2. The Prior Art
With the advent of modern cities came underground utilities such as telephone, sewer and water. The need for access to these underground utilities mandated that they be designed with manholes. To prevent accidents and injury to pedestrians or vehicles moving on the sidewalks and streets, each manhole is provided with a cover. These manhole covers come in a variety of sizes, from small ones weighing only a few pounds, to large ones weighing several hundred pounds.
To gain access to a manhole requires first removing the manhole cover. Originally, manhole covers were removed by hand, using simple tools such as a pry bar or stick. Small, lightweight manhole covers could safely be removed this way. However, for larger and heavier manhole covers, this method presented a variety of safety problems including strained muscles experienced in removing the cover, mashed toes from moving it away from the manhole, and mashed fingers from replacing it on the manhole.
An early improvement on the simple pry bar can be seen in U.S. Pat. No. 2,086,318 where small wheels and adjustable gripper members were added to a simple pry bar. However, this invention still required the user to stoop down and exert a substantial upward pull on the end of the bar in order to lift a large manhole cover.
U.S. Pat. No. 4,482,182 added an upward oriented T-shaped handle to a pry bar to allow a person to lift a manhole cover without stooping over. However, that invention had no wheels and thus, the user had to drag the invention and the manhole cover once the manhole cover was lifted off of the manhole. Also, that invention did not adjust to fit different sizes of manholes.
Finally, U.S. Pat. No. 4,838,521 added small wheels, a telescoping T-shaped handle, adjustable grippers, and a pry bar which would lay near the handle in an inoperative, or storage, position. That invention, however, was not readily adjustable between widely varying sized manhole covers because of the fixed length of the shaft on which one set of grippers were attached. Each adjustment between very large and very small manhole covers required replacement of the shaft on the invention.
The present invention overcomes these problems by providing an inverted U-shaped frame and an L-shaped handle which can be used either together or alone to lift even large manhole covers without stooping or straining, large rubber wheels for easily moving the cover once it has been lifted, a lift bar which can be adjusted without tools to various lengths and can be reversed within a pivotal sleeve to employ a different gripper shape in lifting a manhole cover. Also, the lifting bar of the present invention stores against the frame for ease in transporting of the invention in an inoperative position.